Vacuum relay



June 1967 v E. DE LUCIA VACUUM RELAY Filed Aug. 1e, 1965 United States Patent O 3,324,430 VACUUM RELAY Victor E. De Lucia, 927 Euclid Ave., Santa Monica, Calif. 90403 Filed Aug. 16, 1965, Ser. No. 479,759 2 Claims. (Cl. 335-84) The present invention relates to vacuum relays, and it relates more particularly to an improved, miniature, highvoltage magnetic latching vacuum relay.

The improved magnetic latching vacuum relay of this invention is of the same general type as disclosed and claimed in copending application Ser. No. 462,260, liled June 8, 1965. However, the present invention is concerned with an improved highly sensitive, miniature, magnetic latching vacuum relay which is capable of extremely high voltage operation.

As pointed out in the copending application, the present day use of miniature vacuum relays is Widespread; and such relays find utility, for example, in space vehicles, missiles, and the like.

The relay described in the copending application, and the relay of the present invention, are particularly advantageous in that they are capalble of withstanding extremely high voltages across their contacts without experiencing spurious contact closure due to the resulting electrostatic fields; and also in that they are capable of responding to extremely brief pulses of one polarity or the other, and of l-atching magnetically in a first or second switching condition, in response to such pulses.

The relay of the present invention, as mentioned, like that of the copending application, is capable for use under extremely high voltage conditions, and of operating with a magnetic latching action in response to extremely brief pulses of one polarity or the other.

The improved relay of the present invention, like that of the copending case, may use, for example, a bistable magnetic element which may be composed of a magnetic alloy known in the art as Remendun This is a vanadium, cobalt `and iron alloy which has been recently developed bythe Bell Telephone Laboratories. The alloy is described, for example, in the Bell Laboratories Record for March 1964.

Remendur is composed, for example, of 2.5% vanadium, 49% cobalt, and 48.5% iron. This magnetic alloy is capable of high remanence, for example, up to 25,500 gauss. The alloy also has an essentially square hysteresis loop for ecient switching operation. It has a comparatively stable coercive force in the range of 2OL60D oersteds.

Moreover, Remendur has suliicient malleability and ductility to permit it to lbe processed into thin strips. It can be easily electro-plated in order to increase its electrical conductivity. When a movable contact member in a relay is formed of Remendur and when the relay coil is magnetically pulsed by electric pulses of one polarity or the other, the movable contact is thereby caused to assume corresponding iirst and second magnetic remnant condition.

For example, when the relay coil is pulsed so that the movable contact member is changed from one magnetic remnant condition to the other, the magnetic change is instantaneous, and it may be produced by ank extremely brief electric pulse. This means that the response of the 3,324,430 Patented .lune 6, 1967 rice relay movable member itself need not be instantaneous. Rather, the movable contact member is subsequently at tracted to one of the fixed contacts or the other of the relay, as will Ibe described, after it has changed its magnetic remnant condition. In this manner, the relay is changed from one switching state to another, and it remains in the latter switching state until an opposite polarity pulse applied to the relay coil changes the remnant condition of the movable Contact member back to its original state.

Permanent magnets are employed in the embodiment of the invention to be described, so as to establish the fixed contacts of the relay with a selected magnetic polarity. These permanent magnets are positioned externally of the envelope, and are in engagement with the fixed contacts of the relay; the fixed contacts being composed of magnetizable material and extending through the walls of the evacuated envelope.

As mentioned above, the improved relay of the invention is capable of responding to extremely brief actuating pulses. This is -because the latching operation of the relay does not depend upon actual movement of its movable contact 'before it may become effective. Instead, a brief pulse applied to the energizing coil of the relay immediately changes the state of the remnant magnetization of the movable contact of the relay, and the movable contact member is attracted to one or the other of the fixed contacts, and repelled `by the other, as will -be described.

In the constructed embodiment to be described, the movable contact of the relay is positioned for pivotal movement between two magnetic poles of opposite polarity. The magnetic poles may also serve as xed contacts for the relay. These poles extend through the wall of the evacuated envelope of the relay; and they are oppositely magnetized by respective external permanent magnets, or by other appropriate magnetizing means.

Then, when the movable contact is magnetized with one polarity, it is repelled by one of the fixed contact magnetic poles and is attracted by the other, so that the movable contact is moved from'one switching condition to the other. Then, when the movable contact is magnetized with the opposite polarity, the reverse action occurs `and the movable contact member is moved back to its iirst switching condition.

When the movable contact is composed of a material such as Remendur, a brief pulse will instantaneously establish the movable contact in one or the other of its magnetic conditions. This permits the movable contact to move to one switching condition or the other, and to remain :firmly established in the particular switching condition until the relay is energized by an opposite polarity pulse. It is, accordingly, an object of the present invention to provide an improved high voltage magnetic latching vacuum relay Which may be of the single pole, double throw type and .which exhibits bistable latching characteristics.

Another object of the invention is to provide such an improved high voltage magnetic latching vacuum relay which can be actu-ated from one of its latched switching conditions to the other -by an extremely |brief electric pulse.

A further object of the invention is to provide such an improved relay which utilizes a lowmass, low inertia armature, and which does not exhibit any tendency towards spurious operation, even in the presence of excessively high extraneous vibratory or shock conditions.

Yet another object of the invention is to provide such an improved vacuum relay which is capable of being securely held in either of its switching positions; and which is capable, as noted, as withstanding a high degree of shock or vibration without exhibiting spurious switching action; and yet which may be actuated from one switching condition to the other by a brief, low energy pulse.

Other objects and advantages of the invention will become apparent from a consideration of the following description, when the Idescription is taken in conjunction with the accompanying drawing in which:

FIGURE l is a perspective view of an improved vacuum relay constructed in accordance with one embodiment of th-e invention; and

FIGURE 2 is a sectional view on an enlarged scale showing in schematic form, the constructional details of the improved relay of the invention.

A constructed embodiment of the high voltage, high vacuum single-pole, double-throw latching relay of the invention has been found capable of operating at voltages up to `5 kilovolts at 1500* volt-amperes. The particular embodiment weighs less than one ounce and measures approximately inch by 2 inches.

As pointed out above, and as will be described in detail hereinafter, the relay of the invention can be switched from one switching condition to another with short, lowenergy pulses, these pulses being as short as 50 microseconds. Moreover, the contacts of the relay yare lsecurely maintained in the switched' position without `any further consumption of electric power in lohe relay coil. Because of the short duration 'of the activating pulse, the temperature rise of the relay coil isv virtually eliminated. Application of the pulse to the relay coil can be controlled by means of a manually operated switch or a pulse generator.

With reference to the drawings, it will be observed that the improved vacuum relay of the present invention, in the illustrated embodiment, includes .an elongated evacuated envelope composed, for example, of glass or other appropriate substance. An elongated, movable contact member 12 is pivotally mounted in the evacuated envelope 10 by means, for example, of a resilient wire-like member 14.

The resilient member 14, in turn, is supported by a rigid rod, or pin, 16. The pin 16 is sealed to` the envelope and extends through the envelope. The pin 16 serves as a support for the spring 14 and movable contact 12, and it also serves as an electrical terminal.

The pin 16 and resilient wire 14 may be composed, for example, of tungsten. The movable contact member 12 may be composed of Remendur or of other appropriate magnetizable material.

It is preferred that the movable contact member be composed of a material such as Remendulrj so that it will respond instantaneously to a brief magnetizing pulse, and so that it will exhibit a rst or a second remnant magnetic state. The pulse is applied for example, to a relay coil 17 which is supported externally of the envelope 10, as shown in FIGURE 1.

A pair 'of tixed contact buttons 18 composed, for example, of tungsten, or of other suitable material, are mounted on the free end of the movable contact member 12.

A pair of magnetic pole pieces 20 and 22 are mounted in the envelope 10 adjacent the free end of the movable contact member 12, and on Iopposite sides of the movable contact member. As shown in FIGURE 2, the magnetic pole pieces 20l and 22 extend along an axis which traverses the longitudinal axis of the envelope 10. These pole pieces are composed of magnetizable material, such as a Kovar, and they are sealed to the envelope and extend through the wall yof the envelope 10.

The pole pieces 20 and 22 function as fixed contacts for the relay, and appropriate contact buttons 24 and 26, composed of tungsten, or other suitable material, are aiiixed to their inner ends. The movable contact member 12 is controlled so as to close its contact buttons 18 with the pole piece 20, or with the pole piece 22.

A pair of external permanent magnets 28 and 30 are affixed respectively to the pole pieces 20 and 22. These permanent magnets have the illustrated polarity, for example, so as to establish the pole pieces at opposite polarity. Electrical contacts 32 and 34 (FIGURE 1) are wrapped around the protruding portions of the -respective pole pieces 20 and 22, and around the adjacent permanent magnets 28 and 30. A similar terminal 36 may be wrapped around the terminal rod 16.

When a brief electrical pulse of a particular polarity is applied to the terminals 40ct the coil 17, the movable Contact member 12 is established in a -rst magnetic state or in a second magnetic state. Should it be established in the first magnetic state, for example, it is attracted by the xed contact pole piece 20* and repelled by the fixed contact pole piece 22. Therefore, the movable contact 12 is moved into contact engagement with the pole piece 20. Moreover, the movable contact 12 is held firmly in engagement with the pole piece 20, due to the magnetic attraction of the pole piece 2 0 and the repelling action of the pole piece 22, until the magnetic condition of the movable contact is reversed.

Then, should a brief electric pulse of opposite polarity be applied to the terminals 40 of the relay coil 17, the opposite magnetic condition occurs, and the movable contact 12 is brought into engagement with the pole piece 22.

It will be appreciated that whenever the relay of the invention is actuated to one switching state or another, it is rmly held in its actuated switching state, due to the magnetic attraction of the engaged pole piece and the magnetic repelling action of the other pole piece.

The low inertia of the armature, coupled with the magnetic forces, renders the relay immune to the effects of external shocks or vibrations. Moreover, the actuating pulse can be immediately discontinued without affecting the switched state of the relay, so that there is no need for continuous current to flow in the relay coil.

It will be appreciated that while a particular embodiment of the invention has been described, modifications may be made. It is intended in the claims to cover the modications which come within the scope of the invention.

What is claimed is:

1. A magnetic latching relay including: an evacuated envelope; an electrically conductive terminal pin extending into said envelope along a first axis; an elongated movable electrically conductive armature member composed of a high remanence bi-stable magnetic material having an essentially square hysteresis loop and capable of exhibiting irst and second states of remnant-'magnetization positioned within said envelope to extend essentially along said iirst axis and resiliently coupled to said-terminal pin t-o be supported thereby in electrical contact therewith; a lirst pair of Contact buttons of electrically conductive material mounted on said movable armature member on opposite faces thereof in electrical contact therewith and adjacent the free end thereof remote from said terminal pin; a pair of rod-shaped magnetizable iixed contact members extending through said envelope at opposite sides thereof and extending along a second axis aligned with said rst pair of contact buttons on said movable armature member and traversing said rst axis; a further pair of contact butt-ons of electrically conductive material respectively mounted on the inner ends of said xed contact members in electrical contact therewith and spaced from said iirst pair of contact buttons to be selectively engaged thereby as the free end of said movable armature member moves from one side 5, to the other of said rst axis; and permanent magnetic means mounted externally of said envelope and in engagement with the respective outer ends of said fixed contact members for magnetizing said ixed contact members with yopposite magnetic polarities, so as to` cause said armature selectively to move against and latch with one of said fixed contact members or the other as determined by the state of remnant magnetization of said armature.

2. The relay dened in claim 1 and which includes an electrical energizing coil mounted on said envelope and responsive to brief electric pulses of a rst or second polarity for selectively establishing the state of remnant magnetization of said movable armature member, so as to cause said armatureinember to be subsequently attracted to one of said xed contact members or the other.

References Cited UNITED STATES PATENTS 2,609,464 9/1952 Brown et al 200-93 X 2,740,915 4/ 1956 Jennings.

3,008,021 11/1961 Pollard 200-93 3,059,075 10/1962 Peek 20Gb-87 10 3,194,921 7/1965 Watts.

BERNARD A. GILHEANY, Primary Examiner. J. BAKER, Assistant Examiner. 

1. A MAGNETIC LATCHING RELAY INCLUDING: AN EVACUATED ENVELOPE; AN ELECTRICALLY CONDUCTIVE TERMINAL PIN EXTENDING INTO SAID ENVELOPE ALONG A FIRST AXIS; AN ELONGATED MOVABLE ELECTRICALLY CONDUCTIVE ARMATURE MEMBER COMPOSED OF A HIGH REMANENCE BI-STABLE MAGNETIC MATERIAL HAVING AN ESSENTIALLY SQUARE HYSTERESIS LOOP AND CAPABLE OF EXHIBITING FIRST AND SECOND STATES OF REMNANT MAGNETIZATION POSITIONED WITHIN SAID ENVELOPE TO EXTEND ESSENTIALLY ALONG SAID FIRST AXIS AND RESILIENTLY COUPLED TO SAID TERMINAL PIN TO BE SUPPORTED THEREBY IN ELECTRICAL CONTACT THEREWITH; A FIRST PAIR OF CONTACT BUTTONS OF ELECTRICALLY CONDUCTIVE MATERIAL MOUNTED ON SAID MOVABLE ARMATURE MEMBER ON OPPOSITE FACES THEREOF IN ELECTRICAL CONTACT THEREWITH AND ADJACENT THE FREE END THEREOF REMOTE FROM SAID TERMINAL PIN; A PAIR OF ROD-SHAPED MAGNETIZABLE FIXED CONTACT MEMBERS EXTENDING THROUGH SAID ENVELOPE AT OPPOSITE SIDES THEREOF AND EXTENDING ALONG A SECOND AXIS ALIGNED WITH SAID FIRST PAIR OF CONTACT BUTTONS ON SAID MOVABLE ARMATURE MEMBER AND TRAVERSING SAID FIRST AXIS; A FURTHER PAIR OF CONTACT BUTTONS OF ELECTRICALLY CONDUCTIVE MATERIAL RESPECTIVELY MOUNTED ON THE INNER ENDS OF SAID FIXED CONTACT MEMBERS IN ELECTRICAL CONTACT THEREWITH AND SPACED FROM SAID FIRST PAIR OF CONTACT BUTTONS TO BE SELECTIVELY ENGAGED THEREBY AS THE FREE END OF SAID MOVABLE ARMATURE MEMBER MOVES FROM ONE SIDE TO THE OTHER OF SAID FIRST AXIS; AND PERMANENT MAGNETIC MEANS MOUNTED EXTERNALLY OF SAID ENVELOPE AND IN ENGAGEMENT WITH THE RESPECTIVE OUTER ENDS OF SAID FIXED CONTACT MEMBERS FOR MAGNETIZING SAID FIXED CONTACT MEMBERS WITH OPPOSITE MAGNETIC POLARITIES, SO AS TO CAUSE SAID ARMATURE SELECTIVELY TO MOVE AGAINST AND LATCH WITH ONE OF SAID FIXED CONTACT MEMBERS OR THE OTHER AS DETERMINED BY THE STATE OF REMNANT MAGNETIZATION OF SAID ARMATURE. 